the idea that the player should be able to aim and shoot at all times.
Thats a good idea... But in some situations not good.
Lets make an example:
The player jumps out of a window with an Front Flip.
After a half rotation he see an enemy and want to shoot on him, so he descides to "aim" (so the screen is rotatet to 180°).
So whats about the landing? in my opinion the player must be break his neck after colliding on the ground?!
But hey, its a game ^^ just decrease the HP value a bit

I really like this Idea, this sounds really funny to me to Jump / climb through the Level.
cYa Sebastian